Revert of Process Statistics header, add max RSS to render_pdfs

dm/DMReporter.cpp

 #include "DMReporter.h"
 
 #include "SkDynamicAnnotations.h"
 #include "SkCommonFlags.h"
 #include "OverwriteLine.h"
-#include "ProcStats.h"
+
+#if defined(SK_BUILD_FOR_UNIX) || defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_ANDROID)
+    #include <sys/resource.h>
+    static long get_max_rss_kb() {
+        struct rusage ru;
+        getrusage(RUSAGE_SELF, &ru);
+    #if defined(SK_BUILD_FOR_MAC)
+        return ru.ru_maxrss / 1024;  // Darwin reports bytes.
+    #else
+        return ru.ru_maxrss;         // Linux reports kilobytes.
+    #endif
+    }
+#else
+    static long get_max_rss_kb() { return 0; }
+#endif
 
 namespace DM {
 
 void Reporter::printStatus(SkString name, SkMSec timeMs) const {
     if (FLAGS_quiet) {
         return;
     }
 
     // It's okay if these are a little off---they're just for show---so we can read unprotectedly.
     const int32_t failed  = SK_ANNOTATE_UNPROTECTED_READ(fFailed);
     const int32_t pending = SK_ANNOTATE_UNPROTECTED_READ(fPending) - 1;
 
     SkString status;
     status.printf("%s%d tasks left", FLAGS_verbose ? "\n" : kSkOverwriteLine, pending);
     if (failed > 0) {
         status.appendf(", %d failed", failed);
     }
     if (FLAGS_verbose) {
-        int max_rss_kb = sk_tools::getMaxResidentSetSizeKB();
-        if (max_rss_kb >= 0) {
-            status.appendf("\t%4dM peak", max_rss_kb / 1024);
+        if (long max_rss_kb = get_max_rss_kb()) {
+            status.appendf("\t%4ldM peak", max_rss_kb / 1024);
         }
         status.appendf("\t%5dms\t%s", timeMs, name.c_str());
     }
     SkDebugf("%s", status.c_str());
 }
 
 void Reporter::fail(SkString msg) {
     sk_atomic_inc(&fFailed);
 
     SkAutoMutexAcquire writer(&fMutex);
     fFailures.push_back(msg);
 }
 
 void Reporter::getFailures(SkTArray<SkString>* failures) const {
     SkAutoMutexAcquire reader(&fMutex);
     *failures = fFailures;
 }
 
 }  // namespace DM